Devices and methods for the treatment of vascular defects

ABSTRACT

Devices and methods for treating vascular defects, such as, for example, balloon-type aneurysms, are described herein. In one embodiment, an apparatus includes an insertion portion and an expandable implant. The expandable implant is configured to be deployed in an aneurysm and is coupled to the insertion portion. The expandable implant has a first portion and a second portion coupled to the first portion. The expandable implant is movable between a first configuration in which the first portion and the second portion are substantially linearly aligned and a second configuration in which the second portion at least partially overlaps the first portion.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. patent application Ser. No.14/603,998, entitled “Devices and Methods for the Treatment of VascularDefects,” filed Jan. 23, 2015, which is a divisional of U.S. patentapplication Ser. No. 13/230,628, now U.S. Pat. No. 8,974,512, entitled“Devices and Methods for the Treatment of Vascular Defects,” filed Sep.12, 2011, which claims priority to and the benefit of U.S. ProvisionalPatent Application No. 61/381,770, entitled “ElectropositiveNeurovascular Endothelialization Device,” filed Sep. 10, 2010, thedisclosures of which are hereby incorporated by reference herein intheir entireties.

BACKGROUND

The invention relates generally to medical devices and more particularlyto expandable medical devices and methods for treating vascular defects.For example, the invention can relate to expandable medical devices andmethods for treating an aneurysm. Aneurysms are dilations in a bloodvessel caused from weakening of a blood vessel wall. The dilation isproduced by the pressure exerted by normal blood flow, which can causethe weakened segment of the blood vessel to swell. In some cases, thisswelling results in a sac, or balloon-like polyp protruding from themain or parent vessel. Continued growth and/or eventual rupture of theballooned arterial wall can have devastating results for a patient. Assuch, unruptured aneurysms should be treated to prevent hemorrhage.Additionally, ruptured aneurysms can be treated to avert a subsequentrupture and/or additional damage.

Some known medical devices and treatment methods used for treating ananeurysm include delivering a platinum coil to the sac of the aneurysm.The platinum coil is electrolytically separated from a delivery wire,thus inducing a charge in the coil which can cause a thrombotic effectin the aneurysm. In known procedures, about 30% of the volume of theaneurysm is packed with coils. Such known devices and methods, however,often have an about 30% recanalization rate, meaning blood flow returnsto the aneurysm again and can cause the coil-packed aneurysm to swellfurther. Additionally, such known devices and methods require prolongedprocedure times for the patient and correspondingly increased exposureto radiation for the patient. Moreover, such devices and methods do nottreat the neck of the aneurysm, which is the area between the parentblood vessel and the sac of the aneurysm.

Another known treatment method includes the use of both a coil and astent. The coil is delivered to the sac of the aneurysm as describedabove, and the stent is positioned within the parent blood vessel suchthat a portion of the stent is disposed over the neck of the aneurysm.Such procedures have several drawbacks. For one, delivery of twoseparate types of devices (i.e., coil(s) and a stent) is a more complexprocedure, often resulting in a longer procedure time for the patient.The stent may lead to intra-stent stenosis of the blood vessel.Additionally, a patient would likely be required to take a blood thinnerindefinitely following the procedure. Moreover, such devices and methodsare not suitable for treatment of aneurysms positioned at a bifurcationof the blood vessel (i.e., between adjacent branches of a vessel).

Another known device and treatment method includes the use of a flowdiverter delivered to the parent blood vessel adjacent the neck of theaneurysm. Generally, the flow diverter is positioned within the parentblood vessel over the neck of the aneurysm to prevent additional bloodflow into the aneurysm from the vessel. In current procedures, more thanone flow diverter is required per aneurysm to ensure blood flow isappropriately diverted from the aneurysm. Such a device and treatmentmethod has similar drawbacks to the use of a stent, described above.Specifically, the flow diverter may lead to stenosis of the blood vesseland the patient would likely be required to take a blood thinnerindefinitely following the procedure. Additionally, known flow divertersare not suitable for treating an aneurysm positioned at a bifurcation ofthe blood vessel. Moreover, long term follow-up of patients treatedusing a flow diverter is showing an increased rate of recanalization tothe aneurysm.

Thus, there is a need for improved systems, devices and methods fortreating vascular defects, such as balloon-type aneurysms, as describedherein.

SUMMARY

Devices and methods for treating vascular defects, such as, for example,balloon type aneurysms, are described herein. In one embodiment, anapparatus includes an insertion portion and an expandable implant. Theexpandable implant is configured to be deployed in an aneurysm and iscoupled to the insertion portion. The expandable implant has a firstportion and a second portion coupled to the first portion. Theexpandable implant is movable between a first configuration in which thefirst portion and the second portion are substantially linearly alignedand a second configuration in which the second portion at leastpartially overlaps the first portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a medical device according to anembodiment in a first configuration.

FIG. 2 is a schematic illustration of a medical device according to anembodiment in a second configuration.

FIG. 3 is a side view of a medical device according to an embodiment ina first configuration.

FIG. 4 is a side view of a medical device according to an embodiment ina second configuration.

FIG. 5A is a view of the medical device of FIG. 3 in a firstconfiguration during insertion into an aneurysm.

FIG. 5B is a view of the medical device of FIG. 3 in a secondconfiguration during insertion into an aneurysm.

FIG. 5C is a view of the medical device of FIG. 3 in a thirdconfiguration during insertion into an aneurysm.

FIG. 6 is a view of a portion of a medical device in an expandedconfiguration, according to an embodiment.

FIGS. 7-13 are views of a medical device in an expanded configuration,according to embodiments.

FIG. 14 is a view of a medical device in a partially collapsedconfiguration, according to an embodiment.

FIG. 15 is a view of the medical device of FIG. 14 in an expandedconfiguration, according to an embodiment.

FIG. 16 is a view of a portion of a medical device in an expandedconfiguration according to an embodiment, with a first portion spacedapart from a second portion.

FIG. 17A is a view of a portion of a medical device in a collapsedconfiguration according to an embodiment.

FIG. 17B is a view of a portion of a medical device in an expandedconfiguration according to an embodiment.

FIG. 18 is a flowchart of a method according to an embodiment.

DETAILED DESCRIPTION

Medical devices and methods of treatment are described herein to treatpatients experiencing a vascular defect, such as an aneurysm, in acirculatory blood vessel and the effects of that defect, includinghemorrhagic stroke. For example, the devices and methods describedherein can be useful for treating vascular defects present invasculature that is tortuous, of small-diameter, and/or that isotherwise difficult to access. More specifically, the devices andmethods described herein can be useful for treating saccular (alsoreferred to as balloon-type or berry) aneurysms, bifurcation aneurysms,fistulas, and other defects in vasculature, including defects inneurovasculature. The medical devices and methods of treatment describedherein can reduce hemorrhagic events while promoting endothelializationof an opening between an aneurysm and a parent blood vessel from whichthe aneurysm bulge formed (e.g., at a neck of the aneurysm).

Various embodiments of a medical device for occupying all orsubstantially all of the volume of an aneurysm and/or promotingendothelialization at or proximate to the aneurysm are described herein.In some embodiments, the medical device includes an expandable implantincluding an electropositive woven or braided material. The filaments orstrands forming the braid or weave are configured to encouragerecruitment and/or retention of endothelial cells to the device andtherefore within the defect. The expandable implant is configured toassume a non-linear pre-determined three-dimensional shape within a sacof the aneurysm upon release from a tubular or other delivery constraint(e.g., a catheter or cannula). The electropositive woven or braidedmaterial has a particular porosity and includes multiple openingsbetween the filaments or strands when the expandable implant is in theexpanded configuration. Such openings are ideal in the blood environmentfor harboring endothelial cells recruited to the site. Theelectropositivity of the material encourages endothelialization in thepresence of the electronegative charges of the blood and body tissues.Said another way, the electropositivity of the expandable implant inrelation to a charge of blood and tissue (which is electronegative incomparison) provides an environment in the defect that promotesendothelialization. Endothelialization within the defect can ultimatelyresult in the defect walling-off from the parent vessel. For example,the growth and development of an endothelial layer over a neck of ananeurysm can wall off the aneurysm from the parent vessel and allowsflow dynamics to equilibrate at the defect. As such, the device can beconfigured to facilitate healing the defect and preventingrecanalization because tissue is created from within the body thatresists aberrant blood flow and redistributes the flow pressure that mayhave created the defect. Upon healing with endothelialization, thepressure is evenly distributed along the parent vessel in a manner thatprecludes recanalization at the defect post-treatment. Furthermore,blood from within the parent vessel no longer has access to the walledoff defect once the endothelialization process is complete.Additionally, at least a portion of the expandable implant can bepositioned over the neck of the aneurysm once the implant is deployedwithin the aneurysm such that the portion disrupts the flow of bloodfrom the parent vessel into the aneurysm. As such, the expandableimplant provides blood flow disruption in advance of and in addition togrowth and development of the endothelial layer over the neck of theaneurysm.

A medical device described herein can include an insertion portion(e.g., a guide wire) and an expandable implant formed with, for example,woven or braided filaments in a mesh-like configuration. The terms meshand braid can each refer herein to a fabric or material of woven orbraided filaments or strands of wire or polymer. The expandable implantof the medical device can be configured to compress or collapse fordelivery into a blood vessel. In some embodiments, the medical devicecan be inserted while in a collapsed or compressed configuration througha delivery device, such as, for example, a microcatheter, cannula,delivery tube or sheath. In some embodiments, the medical device can bedeployed without the use of such a delivery device.

The expandable implant of the medical device can have a collapsed orcompressed configuration such that the expandable implant has a diameterthat can fit within the narrow constraints of the neurovasculatureand/or within a lumen of a delivery catheter. The expandable implant ofthe medical device can be formed with, for example, an arrangement ofstrands (e.g., a mesh or braid arrangement of strands or filaments) thatcan compress and expand. Such materials include Nitinol, MP35N,stainless steel, cobalt chromium, titanium, platinum, tantalum,tungsten, or alloys thereof, or polyester, polyethylene (PET), Dacron,PEEK, vectron, and suture materials, and are available from Fort WayneMetals of Fort Wayne, Ind., California Fine Wire Company of GroverReach, Calif., other metal manufacturers, Ethicon Inc. of Somerville,N.J., Genzyme of Cambridge, Mass., Poly-Med, Inc. of Anderson, S.C.,and/or other medical grade suture and fiber manufacturers. Theexpandable implant can be compressed over and/or along the insertionportion of the medical device. The insertion portion can be, forexample, a wire. In some embodiments, a medical device includes aninsertion portion movably disposable within a lumen of a deliverydevice. A distal portion of the insertion portion can be coupled to theexpandable implant. The expandable implant can be moved from a collapsedconfiguration to an expanded configuration while disposed within, or asit is being inserted into, a defect (e.g., an aneurysm).

In some embodiments, the expandable implant can be formed with filamentsof superelastic or shape memory material (such as, e.g., nitinol) andthe braid or mesh can be set in a predefined shape prior to attachingthe expandable implant to the insertion portion of the medical device.In such an embodiment, when the expandable implant is deployed andexpands, it assumes a biased predetermined shape. The predeterminedshape can be a generic shape, such as that of a sphere, or can be acustom-made shape based on a shape of a target aneurysm within apatient. Suitable materials are described in more detail herein.

The medical devices described herein can include one or more expandableimplants formed with a woven mesh or braid that has variably sizedapertures (also referred to herein as “openings” or “pores”). Saidanother way, the devices are formed with a material that has aparticular porosity or pore density. In some embodiments, an expandableimplant can have sections of mesh or braid having variation in densityof the filaments and may include portions or bands of densely spacedfilaments (i.e., lower porosity) spaced by portions or bands that areless dense (i.e., higher porosity). The less dense braid portion canhave larger openings in the braid, while the more dense braid portioncan have smaller openings in the braid. Material (e.g., bodily tissuesuch as endothelial cells) can be encouraged to enter and/or attach tointerstices of the mesh of the expandable implant. For example, the moredense braid portion can be used to encourage greater endothelial cellattachment and the less dense braid portion can be used to reduce theoverall weight and or material to be implanted in the patient. The lessdense sections can also direct the final shape of the expandableimplant. For example, sections of less dense (more open) mesh or braidcan direct the effects of expansion of the implant.

In some embodiments, a medical device can be delivered to a desiredtreatment site within a vasculature by inserting the medical devicethrough a lumen of a delivery catheter (e.g., a microcatheter). Theexpandable medical device can be inserted through the delivery catheterin a collapsed or compressed configuration. The expandable implant ofthe expandable medical device can be moved out through a distal end ofthe delivery catheter at the treatment site (e.g., into a sac of ananeurysm) and moved to an expanded configuration. In some embodiments,the delivery catheter is used to compress or collapse the expandableimplant. For example, the expandable implant can be formed with a biasedexpanded configuration and when it is placed within a lumen of acatheter it is compressed. When the expandable implant is moved outsideof the catheter, it can assume its biased expanded configuration. In theexpanded configuration, a first portion of the expandable implantsubstantially overlaps a second portion of the expandable implant. Thefirst and second portions of the expandable implant can be discretestructures or can be portions of a unitary or monolithically constructeddevice.

A medical device, such as an expandable implant, described herein caninclude a first porous member and a second porous member coupled to thefirst porous member. Each of the first and second porous members includea first end and a second end. The first and second porous members eachhave a collapsed configuration for insertion through a blood vessel andan expanded configuration for occupying at least a portion of the volumedefined by the sac of an aneurysm. In some embodiments, the first porousmember is substantially elongate and has a greater width in its expandedconfiguration than in its collapsed configuration. The second porousmember is substantially elongate and has a greater width in its expandedconfiguration than in its collapsed configuration. In some embodiments,the width of the first porous member is greater than the width of thesecond porous member, for example, when each of the first and secondporous members are in their expanded configurations.

In some embodiments, the first porous member is configured to occupy afirst volume in its collapsed configuration and a second, greater,volume in its expanded configuration. For example, the first porousmember can have a substantially spherical, oblong, or other suitableshape in its expanded configuration that occupies a greater volume thanthe substantially elongate shape of the first porous member in itscollapsed configuration. The second porous member can be configured tomove or curve into a three dimensional configuration in the expandedconfiguration such that a first segment of the second porous memberoverlaps with a second segment of the second porous member. In itsexpanded configuration, the second porous member can define an interiorregion configured to receive the first porous member in its expandedconfiguration. For example, in some embodiments, the second porousmember has a substantially spherical shape with an open interior regionconfigured to receive the first porous member.

In some embodiments, a medical device, such as an expandable implant,described herein can include a first porous member and a second porousmember. Each of the first and second porous members include a first endand a second end. The first and second porous members each have acollapsed configuration for insertion through a blood vessel and anexpanded configuration for occupying at least a portion of the volumedefined by a sac of an aneurysm. The first and second porous members areeach substantially elongate in the collapsed configuration. In itsexpanded configuration, the first porous member has a three-dimensionalshape including a first segment configured to overlap with a secondsegment and defining an interior region. The second porous member isconfigured to be disposed in the interior region of the first porousmember when each of the first and second porous members are in theirrespective expanded configurations. In some embodiments, the secondporous member can be formed integrally or monolithically with the firstporous member. In some embodiments, the second porous member can bewoven or braided using the same filaments that form the first porousmember.

In some embodiments, the expandable implant is in the form of a braidedtube that includes fibers of a superelastic shape memory alloy, orpolymeric fibers. In some embodiments, the expandable implant can effecta shape deformation inducing a substantially spherical contour. In someembodiments, the expandable implant can effect a shape deformationinducing a helical contour. In some embodiments, the shape deformationcan include inducing radial expansion and/or axial shortening.

The medical devices described herein can be used to occupy at least aportion of the volume defined by a sac of an aneurysm and/or to promoteendothelialization of the neck of the aneurysm to inhibit or stop bloodflow into the aneurysm, which can lead to, for example, hemorrhagicstroke. In some embodiments, wire or polymer filaments can be used toform a woven mesh or braided strands that can be expandable, and haveapertures sized to promote endothelial cell attachment at the aneurysm.

It is noted that, as used in this written description and the appendedclaims, the singular forms “a,” “an” and “the” include plural referentsunless the context clearly dictates otherwise. Thus, for example, theterm “a lumen” is intended to mean a single lumen or a combination oflumens. Furthermore, the words “proximal” and “distal” refer todirection closer to and away from, respectively, an operator (e.g.,surgeon, physician, nurse, technician, etc.) who would insert themedical device into the patient, with the tip-end (i.e., distal end) ofthe device inserted first inside a patient's body. Thus, for example,the end first inserted inside a patient's body would be the distal endof the medical device, while the end outside of or inserted later into apatient's body would be the proximal end of the medical device.Additionally, the terms “first,” “second,” “third,” and so on, used todescribe similarly identified elements are for purposes of clarity only,and are not meant to imply a priority or that such numerical identifiermust be associated with that particular element in the claims.

FIGS. 1 and 2 are schematic illustrations of a vascular medical device100 according to an embodiment in a first configuration and a secondconfiguration, respectively. The medical device is configured to promotehealing of an aneurysm. More specifically, at least a portion of themedical device is configured to occupy at least a portion of the volumedefined by a sac of the aneurysm and, in some embodiments, at least aportion of the medical device is configured to promote endothelial cellattachment over a neck of the aneurysm. Once endothelialization over theaneurysm neck is complete, blood flow into the aneurysm sac from aparent blood vessel (i.e., the vessel on which the aneurysm formed) isprevented.

The medical device 100 can include an insertion portion 102 and anexpandable implant 110. The insertion portion 102 is coupled to theexpandable implant 110, such as, for example, at a proximal portion 112of the expandable implant 110. In some embodiments, the insertionportion 102 is removably coupled to the expandable implant 110. In thismanner, the insertion portion 102 can be separated from the expandableimplant 110 following delivery of the expandable implant to the aneurysmand removed from a patient's vasculature. The insertion portion 102 canbe, for example, a guide wire or a distal end portion of a wire. Themedical device 100 can be used with a cannula or catheter 104 (shown indashed lines in FIGS. 1 and 2) to, for example, deliver the expandableimplant 110 to the aneurysm.

The expandable implant 110 is configured to be deployed in the aneurysm(e.g., in a sac of an aneurysm). The expandable implant 110 has a firstportion 120 and a second portion 130. As shown in FIG. 1, the expandableimplant 110 has a first configuration in which the first portion 120 andthe second portion 130 are substantially linearly aligned. In its firstconfiguration, the expandable implant 110 is configured for insertionthrough a blood vessel. The expandable implant 110 is also configuredfor insertion through a neck of the aneurysm when in its firstconfiguration.

The expandable implant 110 is movable between its first configurationand a second configuration in which the second portion 130 at leastpartially overlaps the first portion 120, as shown in FIG. 2. Forexample, the second portion 130 can be configured to bend, curve and/ortwist in multiple turns such that multiple segments of the first portion120 and the second portion 130 are overlapped. Additionally, at leastone of the first portion 120 and the second portion 130 can beconfigured to bend or curve in multiple turns such that the respectivefirst or second portion is overlapped with itself. In some embodiments,the expandable implant 110 can be understood to have multiple firstportions and multiple second portions. In other words, the expandableimplant can continually overlap itself in its deployed configuration tooccupy all or substantially all of the volume of the aneurysm.

In its second configuration, the expandable implant 110 is configured tooccupy at least a portion of the volume defined by the sac of theaneurysm. In some embodiments, when the expandable implant 110 is in itssecond configuration, at least a portion of the expandable implant isconfigured to be positioned over the neck of the aneurysm. For example,the portion of the expandable implant 110 at which the second portion130 overlaps the first portion 120 can be configured to be positionedover the neck of the aneurysm. As such, the portion of the expandableimplant 110 disposed over the aneurysm neck has an increased density(e.g., a dual density compared to the first portion 120 or the secondportion 130 individually), which helps to limit or prevent blood flowfrom entering the sac of the aneurysm. The portion of the expandableimplant 110 positioned over the aneurysm neck can be a scaffold forendothelial cell attachment at the aneurysm neck. For example, theportion of the expandable implant 110 positionable over the aneurysmneck can be porous, such as by including a porous mesh, as described inmore detail herein. In some embodiments, the first portion 120 and thesecond portion 130 of the expandable implant 110 are biased to thesecond configuration.

As noted above, in some embodiments, at least a portion of theexpandable implant 110 is porous. For example, in some embodiments, atleast a portion of the expandable implant 110 can include and/or beconstructed of a mesh (e.g., woven, braided, or laser-cut) material suchthat a wall or layer of the expandable implant 110 defines multipleopenings or interstices 118. More specifically, in some embodiments, atleast one of or both the first portion 120 and the second portion 130 ofthe expandable implant 110 can include the porous mesh. The porous meshcan have a first porosity when the expandable implant 110 is in itsfirst configuration and a second porosity when the expandable implant isin its second configuration. More specifically, in some embodiments, theporous mesh can have a greater porosity when the expandable implant 110is in its second configuration than when the expandable implant is inits first configuration. The porosity of the porous mesh can beincreased, for example, because one or more individual pores or openingsare larger when in the second configuration than in the firstconfiguration. For example, the porous mesh can be expanded in thesecond configuration, thereby increasing the space between filaments ofthe mesh (and thus the size of one or more openings of the mesh). Inother words, an overall volume of pore openings can be increased. Inanother example, the porosity of the porous mesh can be increasedbecause one or more openings that were closed off when the expandableimplant 110 was collapsed into its first configuration are reopened whenthe expandable implant is moved to its second configuration. In otherwords, a number of open pores can be increased.

In some embodiments, the first portion 120 and the second portion 130can have one of the same or different porosities. For example, the firstportion 120 can have a porosity greater than a porosity of the secondportion 130. In another example, the second portion 130 can have aporosity greater than the porosity of the first portion 120. In stillanother example, the first and second portions 120, 130 can havesubstantially equivalent porosities in the expanded configuration.

In some embodiments, at least one of the first portion 120 and thesecond portion 130 includes one, two, three, or more layers. Forexample, in some embodiments, the first portion 120 of the expandableimplant 110 includes a first layer (not shown in FIG. 1 or 2) of porousmesh and a second layer (not shown in FIG. 1 or 2) of porous mesh. Thefirst layer and the second layer can have the same or differentporosities. In some embodiments, the first layer is offset from thesecond layer. As such, the porosity of the first portion is determinedby the porosities of the first and second layers and the manner in whichthe first layer is offset from the second layer.

In some embodiments, at least a portion of the expandable implant 110,such as at least one of the first portion 120 or the second portion 130can include a shape-memory material, such as, for example, nitinol, andcan be preformed to assume a desired shape. Thus, in such an embodiment,the portion of the expandable implant 110 (e.g., the first portion 120and/or the second portion 130) can be biased into an expanded secondconfiguration and moved to a collapsed first configuration byrestraining or compressing the portion of the expandable implant.

In some embodiments, at least a portion of the expandable implant 110,such as at least one of the first portion 120 or the second portion 130can include an electropositive material, described in more detail below.

The expandable implant 110 when in the expanded configuration can have avariety of different shapes, sizes and configurations. For example, insome embodiments, when in the expanded configuration the expandableimplant 110 can be substantially spherical. In some embodiments, theexpandable implant 110 can be substantially helical. In someembodiments, the expandable implant 110 can be substantially circular,disc-shaped, or ring-shaped. In some embodiments, the expandable implant110 can be a custom-made shape based on a shape of a target aneurysmwithin a patient; for example, a shape modeled after the shape of thetarget aneurysm as detected by an imaging device. For example, an imageof the aneurysm shape can be acquired using an angiogram, and theexpandable implant 110 can be modeled after the shape of the aneurysmshown in the angiogram. In some embodiments, the expandable implant 110can include multiple portions having varying outer perimeters or outerdiameters. For example, in some embodiments, when in the expandedconfiguration the expandable implant 110 can include a first portionhaving a first outer perimeter, a second portion having a second outerperimeter and a third portion having a third outer perimeter. In such anembodiment, the second outer perimeter can be smaller than each of thefirst outer perimeter and the third outer perimeter.

In one example use of the medical device 100, a catheter 104 can beinserted into a blood vessel and directed to a desired treatment sitenear a vascular defect, such as the aneurysm. The expandable implant 110is inserted into an elongate lumen of the catheter 104 for delivery tothe treatment site. A distal portion of the catheter 104 is positionedadjacent the aneurysm within the blood vessel. The expandable implant110 is moved from a first position inside the catheter to a secondposition outside the catheter. When the expandable implant 110 is in itsfirst position, each of the first portion 120 and the second portion 130are in a first configuration. For example, in the first configuration,each of the first and second portions 120, 130 can be compressed orcollapsed within the lumen of the catheter 104 and are substantiallylinear in configuration.

The expandable implant 110 can be oriented with respect to an opening inthe vessel wall in fluid communication with the aneurysm such that theexpandable implant can enter a sac of the aneurysm when the expandableimplant 110 is moved to its second position. The expandable implant 110can be moved from its first position to its second position with theassistance of the insertion portion 102 such that the expandable implant110 directed into and positioned within a sac of the aneurysm. When theexpandable implant 110 is in its second position, the first and secondportions each have a second configuration. For example, in the secondconfiguration, each of the first and second portions 120, 130 can beexpanded into a three-dimensional shape. The three-dimensional shape ofthe first portion 120 in the second configuration can be similar to ordifferent from the three-dimensional shape of the second portion 130. Inthe second configuration, the first portion 120 of the expandableimplant 110 substantially overlaps the second portion 130. In someembodiments, the second portion 130 is disposed in an interior regiondefined by the first portion when each of the first portion and thesecond portion are in their respective second configurations.

The first and second portions 120, 130 can be moved to their respectivesecond configurations concurrently or sequentially. For example, in someembodiments, the second portion 130 is moved to its second configurationbefore the first portion 120 is moved to its second configuration. Theexpandable implant 110 can assume a biased expandable configuration suchthat the walls of the expandable implant 110 contact at least a portionof the wall of the aneurysm and/or such that a portion of the expandableimplant is disposed over the neck of the aneurysm. The presence of theexpandable implant 110 over the neck of the aneurysm can substantiallyreduce and/or prevent further blood flow from the parent vessel into theaneurysm sac because the expandable implant can act as a physical flowdisruptor for blood flowing from the parent vessel and as a scaffold forendothelial cell attachment at the aneurysm neck to promoteendothelialization of the neck/vessel wall. The insertion portion 102can then be disconnected from a proximal end of the expandable implant110 and removed through the catheter 104.

FIGS. 3, 4, 5A, 5B and 5C illustrate a medical device according to anembodiment. The medical device 200 can include all or some of the samefeatures and functions as described above for medical device 100. Themedical device 200 includes an insertion portion 202 and an expandableimplant 210. The expandable implant 210 is removably coupled at itsproximal end to a distal end of the insertion portion 202.

The expandable implant 210 includes a first portion 220 and a secondportion 230. As shown in FIGS. 3 and 5A, the expandable implant 210 hasa first, or collapsed, configuration in which the first and secondportions 220, 230 are substantially linearly aligned. In this manner,the expandable implant 210 can be disposed within a lumen of a catheter204 for delivery through a blood vessel V to a treatment site, such asto an aneurysm A. In its first configuration, the expandable implant 210has a first width W1, as shown in FIG. 2. As shown in FIGS. 4 and 5B-5C,the expandable implant 210 is moveable to a second, or expanded ordeployed, configuration. The insertion portion 202 is configured to movethe expandable implant 210 from the first configuration to the secondconfiguration. The insertion portion 202 can be disconnected from theexpandable implant 210 when the expandable implant 210 is in its secondconfiguration.

In its second configuration, the expandable implant 210 is configured tooccupy at least a portion of the volume defined by a sac of the aneurysmA. As such, the expandable implant 210 has a second width W2 in thesecond, expanded, configuration greater than its first width Wi. Forexample, the expandable implant 210 can be substantially narrow andelongate in its first configuration and can assume a three-dimensionalshape in its second configuration. In the embodiments illustrated inFIGS. 3-5C, the expandable implant 210 has a substantially sphericalshape in its second configuration. The expandable implant 210 can becompliant such that its three-dimensional shape can accommodate anyirregularities in the shape of the aneurysm. In the secondconfiguration, the second portion 230 of the expandable implant 210 atleast partially overlaps the first portion 220. At least a portion ofthe expandable implant 210 is configured to be positioned over a neck Nof the aneurysm A when the expandable implant is in its secondconfiguration within the sac of aneurysm A. The expandable implant 210is configured to facilitate endothelial cell attachment at the neck N ofthe aneurysm A, as described in more detail herein.

In the embodiment illustrated in FIG. 3, the first portion (or member)220 is a first ribbon-like strand and the second portion (or member) 230is a second ribbon-like strand discrete from the first portion. In otherembodiments, an expandable implant can include a first portion and asecond portion from a single ribbon-like strand (e.g., integrally ormonolithically constructed), instead of discrete portions. A first end222 of the first portion 220 is coupled to a first end 232 of the secondportion 230. Any suitable mechanism for coupling the first end 222 ofthe first portion 220 to the first end 232 of the second portion 230 canbe used, such as an adhesive, a mechanical coupler, a weld, or the like,or any combination of the foregoing. For example, the first ends 222,232 can be coupled by a band 240. The band 240 can also be configured tohelp couple the insertion portion 202 to the expandable implant 210. Theband 240 can be or can include, for example, a radiopaque marker.

A second end 224 of the first portion 220 and a second end 234 of thesecond portion 230 each have a radiopaque marker 242, 244, respectively,coupled thereto. The radiopaque markers 242, 244 arc configured tofacilitate imaging of the expandable implant 210 during delivery to thetreatment site and/or subsequent to implantation. The markers 242, 244are configured to be wholly disposed within the sac of the aneurysm Awhen the expandable implant 210 is in its second configuration. As such,the markers 242, 244 will not puncture the a wall of the aneurysm A orthe vessel V, and the markers 242, 244 will not interfere withendothelial cell attachment at the aneurysm neck. This is alsobeneficial because if the markers 242, 244 were positioned at orproximate to the neck of the aneurysm, blood from a parent blood vesselcould have a tendency to clot around the marker.

When the expandable member 210 is moved between its first configurationand its second configuration, at least one of the first portion 220 andthe second portion 230 is also moveable between a first configurationand a second configuration. The first portion or member 220 has a first,collapsed, configuration in which the first portion 220 is substantiallyelongate and has a first width. The first portion 220 has a second,expanded, configuration, in which the first portion 220 has a secondwidth greater than the first width. For example, the first portion 220can be moveable from a substantially linear, elongate collapsedconfiguration to a multi-dimensional (e.g., three-dimensional) shape inthe expanded or deployed configuration. As shown in FIGS. 4 and 5C, thefirst portion 220 can have a three-dimensional shape in the expandedconfiguration that lends an overall spherical shape to the expandableimplant 210. The first portion 220 can be biased to its second,expanded, configuration.

The first portion or member 220 is porous and, for example, can includeor be constructed of a porous mesh. The porous mesh can be formed usingfilaments that are woven or braided together in a manner that openingsor interstices are present between portions of the filaments at leastwhen the expandable implant 210 is in its second configuration. Forexample, the porous mesh can include a plurality of braided wires.Suitable mesh material is described in more detail herein. The porousmesh can have a first porosity when the first portion 220 is in thefirst configuration and a second porosity when the first portion 220 isin the second configuration. For example, when the first portion 220 ismoved from its first, collapsed, configuration to its second, expanded,configuration, the mesh can be expanded such that the size of theopenings of the mesh is increased, thus increasing the porosity of themesh. The porous mesh is configured to act as a scaffold that promotesclot formation and endothelium cell attachment when the mesh is disposedwithin the aneurysm A. Specifically, endothelial cells will migrate tothe openings of the mesh.

The first portion 220 of the expandable implant 210 includes a firstlayer of porous mesh and a second layer of porous mesh. In this manner,the density of the first portion 220 is greater than the density ofeither the first or second layers individually. Such a dual-densitystructure can help to limit or prevent blood flow into the aneurysm A,for example when the first and second layers of the first portion 220are disposed over the neck N of the aneurysm A. The first layer ofporous mesh and the second layer of porous mesh can have the sameporosities, or different porosities. The first layer of porous mesh canbe offset from the second layer of porous mesh. In this manner, theoverall porosity of the first portion 220 is greater than the porosityof either the first or second layers individually. The first and secondlayers of porous mesh can be coupled together in any suitable manner.For example, the first portion 220 can be formed using an elongatetubular mesh having an elongate lumen therethrough. In such anembodiment, the elongate mesh can be flattened from a tubular structureto a ribbon-like structure such that a first side, or layer, of the meshis disposed on or proximate to a second side, or layer, of the mesh,thus forming a dual density, or dual-layered, mesh structure.

The second portion, or member, 230 of the expandable implant 210 can beconfigured the same as or similar to, and can be used in the same orsimilar manner, as the first portion 220. When the expandable member 210is moved between its first configuration and its second configuration,the second portion 230 is also moveable between a first, collapsed,configuration in which the second portion is substantially elongate andhas a third width, and a second, expanded, configuration, in which thesecond member has a fourth width greater than the third width. Forexample, the second portion 230 can be moveable from a substantiallylinear, elongate collapsed configuration to a multi-dimensional (e.g.,three-dimensional) shape in the expanded configuration. As shown inFIGS. 4 and 5C, the second portion 230 can have a three-dimensionalshape in the expanded configuration that lends an overall sphericalshape to the expandable implant 210. The second portion 230 can bebiased to its second, expanded, configuration.

The second portion 230 is porous and can include or be constructed of aporous mesh. The porous mesh can be configured the same as or similarto, and can be used in the same or similar manner, as the porous meshdescribed above with respect to the first portion 220 of the expandableimplant 210. For example, the porous mesh can include a weave or braidof filaments that is porous at least when the expandable implant 210 isin its second configuration. Additionally, the porous mesh of the secondportion 230 can have a first porosity when the second portion 230 is inthe first configuration and a second porosity when the second portion230 is in the second configuration. In some embodiments, the secondportion 230 of the expandable implant 210 includes a first layer ofporous mesh and a second layer of porous mesh, which can be of the sameor different porosities. In this manner, the total density of the secondportion 230 is greater than the density of either the first or secondlayers individually. The first layer of porous mesh can be offset fromthe second layer of porous mesh such that the overall porosity of thesecond portion 230 is greater than the porosity of either the first orsecond layers individually. Similarly as described above with respect tothe first portion 220, the first and second layers of porous mesh of thesecond portion 230 can be formed from a monolithically constructedelongate tubular mesh that is flattened into a ribbon-like structure.

The first portion 220 and the second portion 230 of the expandableimplant 210 can be the same or different sizes. For example, as shown inFIG. 5A, the first portion 220 can have a length in its first,collapsed, configuration, that is less than a length of the secondportion 230 in its first, collapsed, configuration. In this manner, themarkers 242, 244 will be sequentially introduced through the neck N ofthe aneurysm A, which permits the expandable implant 210 to beintroduced through a narrower neck N. In another example, the firstportion 220 and the second portion 230 can have the same or differentwidths. In some embodiments, for example, the first width of the firstportion 220 in its first configuration is wider than the third width ofthe second portion 230 in its first configuration. The second width ofthe first portion 220 in its second configuration can also be wider thanthe fourth width of the second portion 230 in its second configuration.In another example, the fourth, expanded, width of the second portion230 can be greater than the second, expanded, width of the first portion220. In some embodiments, the porous mesh of the first portion 220 canhave a multi-dimensional shape with a first width when the expandableimplant 210 is in its second configuration, and the porous mesh of thesecond portion 230 can have a multi-dimensional shape with a secondwidth less than the first width when the expandable implant is in itssecond configuration.

In some embodiments, for example, the first portion 220 (or the porousmesh of the first portion) can have a width of about 8 mm when theexpandable implant is expanded in its second configuration, and thesecond portion 230 (or the porous mesh of the second portion) can have awidth of about 9.5 mm when the expandable implant is expanded in itssecond configuration. As such, in an embodiment in which the firstportion 220 has a smaller overall size in the expanded configurationthan the second portion 230, the first portion 220 can be configured tobe disposed within an open interior region formed by the second portion230 in its second configuration.

In some embodiments, a variation of medical device 200 is contemplated.For example, in such an embodiment, the first portion of the expandableimplant can include a first tubular mesh that defines a lumentherethrough, and the second portion of the expandable implant caninclude a second tubular mesh disposed within the lumen of the firsttubular mesh. The first and second tubular mesh structures can be formedinto a substantially ribbon-like strand. As such, the expandable implanthas a four-layer density. The expandable implant can include additionalribbon-like strands in addition to the strand formed by the first andsecond portions. For example, the expandable implant can include one,two, three, four, five, six, seven, eight, or nine strands, with each ofthe strands having a desired number of layers (e.g., two, four, or morelayers). As such, an expandable implant can be formed that has a desiredamount of density. As noted above, a highly dense structure helps toprevent blood flow from the parent blood vessel into the aneurysm. Eachlayer or portion of the expandable implant can have the same ordifferent density as the other layers or portions. Furthermore, eachlayer or portion of the expandable implant can have the same ordifferent porosity as the other layers or portions.

FIG. 6 illustrates a portion of another embodiment of a medical device.The medical device 300 can include the same or similar features andfunctions as described above for previous embodiments. For example, themedical device 300 includes an expandable implant 310 and an insertionportion or member (not shown in FIG. 6). The expandable implant 310 isshown in an expanded configuration and can be moved between a compressedor collapsed configuration in which the expandable implant issubstantially elongate and the expanded configuration in the same orsimilar manner as described above for expandable implant 210. In theexpanded configuration, a first portion 320 of the expandable implant310 is overlapped by a second portion 330 of the expandable implant.Additionally, at least a portion of the first portion 320 is disposedwithin an open interior region 336 defined by the second portion 320when the expandable implant 310 is in its expanded configuration.

The expandable implant 310 includes a ribbon-like strand of porous mesh.At least a portion of the porous mesh is configured to be positionedover a neck of an aneurysm with the expandable implant 310 is in theexpanded configuration. The porous mesh is configured to bend, curve,and/or twist at multiple turns into a substantially spherical shape whenthe expandable implant 310 is in the expanded configuration. The porousmesh can be a ribbon-like structure that is wider than the porous meshof expandable implant 210. In this manner, the porous mesh of expandableimplant 310 can be a shorter length than that of expandable implant 210and still provide a similar amount of coverage within the aneurysm (andover the neck of the aneurysm) as expandable implant 210. The porousmesh can include one, two, or more layers depending on the desireddensity and porosity of the expandable implant 310. In some embodiments,a first radiopaque marker 342 is coupled to a first end 312 of theexpandable implant 310 and a second radiopaque marker 344 is coupled toa second end 314 of the expandable implant. The expandable implant 310is configured to be wholly disposed within the aneurysm such that theradiopaque markers 342, 344 are wholly disposed within the aneurysm sacand the porous mesh is disposed over the neck of the aneurysm. In someembodiments, the radiopaque markers are configured to be positioned at aside of the aneurysm (i.e., disposed away from the neck of theaneurysm).

FIG. 7 illustrates another embodiment of a medical device. The medicaldevice 400 can include the same or similar features and functions asdescribed above for previous embodiments. For example, the medicaldevice 400 includes an expandable implant 410 and an insertion portionor member 402. The expandable implant 410 is sized to occupy the sac ofan aneurysm, and the insertion member 402 is configured to facilitatedelivery of the expandable implant into the sac of the aneurysm. Theexpandable implant 410 is shown in an expanded configuration and can bemoved between a compressed or collapsed configuration and the expandedconfiguration in the same or similar manner as described above forprevious embodiments.

The expandable implant 410 includes at least one ribbon-like strand ofporous mesh configured to be expanded within the aneurysm as a 360degree spiral or ring-shaped structure. In the expanded configuration, afirst portion 420 of the expandable implant 410 is overlapped by asecond portion (not shown in FIG. 7) of the expandable implant, which isoverlapped by a third portion 450 of the expandable implant. In thismanner, at least a portion of the expandable implant 410 includes two,three, four, or more layers of implant material (e.g., porous mesh, asdescribed above in previous embodiments), which can be positioned overthe neck of the aneurysm from within the aneurysm to function as a denseflow disrupter. In some embodiments, a radiopaque marker 442 is coupledto the expandable implant 410.

FIG. 8 illustrates another embodiment of a medical device. The medicaldevice 500 can include the same or similar features and functions asdescribed above for medical device 400. For example, the medical device500 includes an expandable implant 510 and an insertion portion ormember 502. The medical device 500 can be delivered to an aneurysm orother vascular defect using a microcatheter 504. The expandable implant510 is sized to occupy at least a portion of the volume defined by thesac of the aneurysm, and the insertion member 502 is configured tofacilitate delivery of the expandable implant into the sac of theaneurysm. The expandable implant 510 is shown in an expandedconfiguration and can be moved between a compressed or collapsedconfiguration and the expanded configuration in the same or similarmanner as described above for previous embodiments.

The expandable implant 510 includes a porous mesh configured to beexpanded within the aneurysm as a substantially circular or disc-shapedstructure, as shown in FIG. 8. In the expanded configuration, a firstend portion 512 of the expandable implant 510 is engaged with and/oroverlapped with a second end portion 514 of the expandable implant. Theexpandable implant 510 includes a first portion 520 having a firstdensity of porous mesh and a second portion 530 having a second, higher,density of porous mesh. More specifically, a weave or braid of theporous mesh has a higher density in the second portion 530 than in thefirst portion 520 of the expandable implant. The expandable implant 510is configured to be disposed within the aneurysm (or other vasculardefect) such that at least a portion of the second portion 530 isdisposed over the neck of the aneurysm, because the higher densitypromotes endothelial cell attachment to the expandable implant. Theexpandable implant 510 includes at least one radiopaque marker 542,which can be disposed on one of the first end portion 512 (as shown inFIG. 8) and/or the second end portion 514. When the expandable implant510 is disposed within the aneurysm in its expanded configuration suchthat the higher density second portion 530 is disposed over the neck ofthe aneurysm, the at least one radiopaque marker 542 is disposed withinthe sac of the aneurysm away from the neck of the aneurysm.

FIG. 9 illustrates another embodiment of a medical device. The medicaldevice 600 can include the same or similar features and functions asdescribed above for previous embodiments. For example, the medicaldevice 600 includes an expandable implant 610 and an insertion portionor member 602. The expandable implant 610 is sized to occupy at least aportion of a volume defined by the sac of the aneurysm, and theinsertion member 602 is configured to facilitate delivery of theexpandable implant into the sac of the aneurysm. The expandable implant610 is shown in an expanded configuration and can be moved between acompressed or collapsed configuration and the expanded configuration inthe same or similar manner as described above for previous embodiments.

The expandable implant 610 includes a ribbon-like strand of porous meshhaving at least two layers of mesh. The expandable implant 610 isconfigured to be expanded within the aneurysm as a substantially helicalor coil shaped structure, as shown in FIG. 9. The expandable implant 610can be disposed within the aneurysm (or other vascular defect) such thatat least a portion of the implant is disposed over the neck of theaneurysm to facilitate endothelial cell attachment at the neck. Theexpandable implant 610 includes at least one radiopaque marker 642,which can be disposed on an end of the expandable implant 610, as shownin FIG. 9. The insertion member 602 can be removably coupled to theexpandable implant at the radiopaque marker.

FIG. 10 illustrates another embodiment of a medical device. A medicaldevice 700 includes all the same or similar features and functions asdescribed above for medical device 600. For example, the medical device700 includes an expandable implant 710, an insertion portion or member702, and a radiopaque marker 742 coupled to an end of the expandableimplant. The expandable implant 710 includes a porous mesh formed of atubular or rounded braid structure. The rounded braid structure can lendmore softness to the expandable implant 710 than, for example, theflattened ribbon-like structure previously described.

FIG. 11 illustrates another embodiment of a medical device. The medicaldevice 800 can include the same or similar features and functions asdescribed above for previous embodiments. For example, the medicaldevice 800 includes an expandable implant 810 and an insertion portionor member 802. The medical device 800 can be delivered to an aneurysm orother vascular defect using a microcatheter 804. The expandable implant810 is sized to occupy at least a portion of the volume of the sac ofthe aneurysm, and the insertion member 802 is configured to facilitatedelivery of the expandable implant from the microcatheter 804 into thesac of the aneurysm. The expandable implant 810 is shown in an expandedconfiguration and can be moved between a compressed or collapsedconfiguration and the expanded configuration in the same or similarmanner as described above for previous embodiments.

The expandable implant 810 includes a first member 820 and a secondmember 830. The first and second members 820, 830 are coupled at a firstend 812 of the expandable implant 810 and a second end 814 of theexpandable implant. The first and second members 820, 830 are alsocoupled together at at least one middle portion of the expandableimplant 810 between the first end 812 and the second end 814. The firstand second members 820, 830 can be coupled, for example, usingradiopaque markers 842, 844, 846. Each site of coupling is configured tobe a folding point of the expandable implant 810 when the expandableimplant is delivered into the aneurysm and is expanded within theaneurysm to comply with the shape of the aneurysm. As such, theexpandable implant 810 can be more densely packed into the aneurysm, forexample, as compared to an implant that cannot bend or fold in responseto the shape of the aneurysm. At least one of the first member 820 andthe second member 830 of the expandable implant 810 includes a porousmesh formed of a tubular or rounded braid structure.

FIG. 12 illustrates another embodiment of a medical device. The medicaldevice 900 can include the same or similar features and functions asdescribed above for previous embodiments. For example, the medicaldevice 900 includes an expandable implant 910 and an insertion portionor member 902. The expandable implant 910 is sized to occupy the sac ofthe aneurysm, and the insertion member 902 is configured to facilitatedelivery of the expandable implant from a microcatheter (not shown inFIG. 12) into the sac of the aneurysm. The expandable implant 910 isshown in an expanded configuration and can be moved between a compressedor collapsed configuration and the expanded configuration in the same orsimilar manner as described above for previous embodiments.

The expandable implant 910 includes a series of expandable portions 920,922, 924, 926, 928 separated by a series of constricted portions 930,932, 934, 936. The expandable portions 920, 922, 924, 926, 928 can beconfigured to expand to any suitable multi-dimensional shape, including,for example, that resembling a sphere, a disc, a parabola, or the like.Additionally, each expandable portion 920, 922, 924, 926, 928 can havean expanded shape distinct from an expanded shape of another expandableportion.

When the expandable implant 910 is in its expanded configuration, asshown in FIG. 12, the expandable portions 920, 922, 924, 926, 928 aremore porous and less dense then the constricted portions 930, 932, 934,936. The density and/or porosity of each expandable portion 920, 922,924, 926, 928 can be varied from the other expandable portions 920, 922,924, 926, 928, and the density and/or porosity of each expandableportion 920, 922, 924, 926, 928 can be varied along a length and/orwidth of the respective expandable portion. For example, a firstexpandable portion 920 can be more dense and/or less porous proximate toa first constriction portion 930 and less dense and/or more porous at amiddle, wider portion of the first expandable portion 920. Additionally,the expandable portions 920, 922, 924, 926, 928 are each configured tohave a width greater than when the expandable implant 910 is in itscollapsed configuration, and the constricted portions 930, 932, 934, 936are each configured to have a width narrower than a width of theexpandable portions 920, 922, 924, 926, 928. As such, the expandableimplant 910 is configured to bend, curve, and/or fold at the constrictedportions 930, 932, 934, 936 to help comply with the shape of theaneurysm.

When the expandable implant 910 is in its expanded configuration, thefirst expandable portion 920 is configured to have a width greater thanthe width of the other expandable portions 922, 924, 926, 928. The firstexpandable portion 920 can be, as illustrated in FIG. 12, the mostproximal of the expandable portions 920, 922, 924, 926, 928. The firstexpandable portion 920 is configured to be positioned over a neck of theaneurysm when the expandable implant 910 is disposed within the aneurysmin its expanded configuration. In this manner, the first expandableportion 920 is configured to act as a flow disruptor at the neck of theaneurysm to help limit the flow of blood into the aneurysm from theparent blood vessel. The remaining, more distal, expandable portions922, 924, 926, 928 are configured to be packed into the aneurysm toembolize the aneurysm.

The expandable implant 910 includes a first radiopaque marker 942coupled to a first end 912 of the implant and a second radiopaque markercoupled to a second end 914 of the implant. The radiopaque markers 942,944 are configured to be wholly disposed within the sac of the aneurysmwhen the expandable implant 910 is disposed in the aneurysm in itsexpanded configuration.

FIG. 13 illustrates another embodiment of a medical device. The medicaldevice 1000 can include the same or similar features and functions asdescribed above for previous embodiments. For example, the medicaldevice 1000 includes an expandable implant 1010 and an insertion portionor member 1002. The expandable implant 1010 is sized to occupy the sacof the aneurysm, and the insertion member 1002 is configured tofacilitate delivery of the expandable implant into the sac of theaneurysm. The expandable implant 1010 is shown in an expandedconfiguration and can be moved between a compressed or collapsedconfiguration and the expanded configuration in the same or similarmanner as described above for previous embodiments.

The expandable implant 1010 includes a first porous member 1020 and asecond porous member 1030. The first porous member 1020 includes aporous mesh configured to have a multi-dimensional shape when theexpandable implant 1010 is in its expanded configuration. As such, thefirst porous member 1020 has a second width in the expandedconfiguration that is greater than a first width of the first porousmember in the collapsed configuration. The first porous member 1020 canbe configured to expand to any suitable multi-dimensional shape,including, for example, that resembling a parabola, as shown in FIG. 13,a sphere, a disc, or the like. The first porous member 1020 isconfigured to be positioned over a neck of the aneurysm when theexpandable member 1010 is disposed within the sac of the aneurysm todisrupt and/or stop the flow of blood into the aneurysm from the parentblood vessel. Additionally, the porous mesh of the first porous member1020 is configured to promote endothelial cell attachment at the neck ofthe aneurysm, which can help to heal over the neck of the aneurysm.

The second porous member 1030 includes a porous mesh configured to havea multi-dimensional shape when the expandable implant 1010 is in itsexpanded configuration. As such, the second porous member 1030 has afourth width in the expanded configuration greater than a third width ofthe second porous member in the collapsed configuration. The secondporous member 1030 can be configured to expand to any suitablemulti-dimensional shape, including, for example, that resembling a tube,as shown in FIG. 13, a sphere, a disc, a parabola, or the like. In theembodiment illustrated in FIG. 13, the second width of the first porousmember 1020 is greater than the fourth width of the second porous member1030. The second porous member 1030 is configured to be disposed withinthe sac of the aneurysm such that the first porous member 1020 isdisposed between the second porous member 1030 and the neck of theaneurysm. The second porous member 1030 is configured to be packed intothe aneurysm to embolize the aneurysm.

A radiopaque marker 1044 is disposed between the first porous member1020 and the second porous member 1030, and can be used to couple thefirst and second porous members. The expandable implant 1010 isconfigured to bend, curve, and/or fold at the radiopaque marker 1044,which can help the expandable implant 1010 comply with the shape of thesac of the aneurysm. Another radiopaque marker 1042 can be disposed on aproximate end of the expandable implant 1010, and can be used to couplethe insertion portion 1002 to the expandable implant. The radiopaquemarkers 1042, 1044 are configured to be wholly disposed within the sacof the aneurysm when the expandable implant 1010 is disposed in theaneurysm in its expanded configuration.

FIGS. 14-15 illustrate another embodiment of a medical device. Themedical device 1100 can include the same or similar features andfunctions as described above for previous embodiments. For example, themedical device 1100 includes a first porous member 1120, a second porousmember 1130, and an insertion portion or member 1102 removably couplableto the first and second porous members 1120, 1130.

The first porous member 1120 has a first end 1122 and a second end 1124.As shown in FIG. 14, the first porous member 1120 has a collapsedconfiguration for insertion through a blood vessel. In its collapsedconfiguration, the first porous member 1120 is substantially elongatewith a first length. As shown in FIG. 15, the first porous member 1120has an expanded configuration for occupying a sac of an aneurysm. Whenthe first porous member 1120 is in its expanded configuration, it has athree-dimensional shape and defines an open interior region 1126. Thefirst porous member 1120 can have any suitable three-dimensional shape.For example, the first porous member 1120 can be configured to curvedinto a substantially spherical shape, as shown in FIG. 15. Additionally,in its expanded configuration, the first porous member 1120 includes afirst segment configured to overlap with a second segment, which can besimilar in many respects as described above with respect to expandableimplants 210 and 310, for example For example, the first porous member1120 can include a mesh having a first segment configured to overlapwith a second segment of the porous mesh to form a higher densityportion of the first porous member 1120.

The second porous member 1130 has a first end 1132 and a second end1134. The second porous member 1130 has a collapsed, first,configuration (not shown in FIG. 14 or 15) for insertion through a bloodvessel. In its collapsed configuration, the second porous member 1130 issubstantially elongate with a second length less than the first lengthof the first porous member, and is configured to occupy a first volume.As shown in FIGS. 14 and 15, the second porous member 1130 has anexpanded, second, configuration for occupying at least a portion of thevolume of the sac of the aneurysm. When the second porous member 1130 isin its expanded configuration, it has a three-dimensional shape and isconfigured to occupy a second volume greater than the first volume. Thesecond porous member 1130 can have any suitable three-dimensional shape.For example, the second porous member 1130 can be configured to expandinto a substantially ball (e.g., spherical, round, oblong, or the like)shape, as shown in FIGS. 14 and 15. In the expanded configuration, thesecond porous member 1130 can have a porosity the same as, or differentthan, a porosity of the first porous member 1120. The second porousmember 1130 is configured to be disposed in the interior region 1126 ofthe first porous member 1120 when each of the first porous member andthe second porous member are in the deployed or expanded configurations.

In the embodiment illustrated in FIGS. 14 and 15, the second porousmember 1130 is coupled to the first porous member 1120. Specifically,the first end 1122 of the first porous member 1120 is coupled to thefirst end 1132 of the second porous member 1130. At least one of thefirst porous member 1120 and the second porous member 1130 includes aradiopaque marker. As shown in FIG. 14, a first radiopaque marker 1142can be disposed on the first ends 1122, 1132 of the first and secondporous members 1120, 1130 to couple the first and second porous memberstogether. A second radiopaque marker 1144 can be disposed on the secondend 1134 of the second porous member 1130. When the first and secondporous members 1120, 1130 are in their respective expandedconfigurations, the second radiopaque marker 1144 is disposed within theinterior region defined by the first porous member 1120.

In use, the first and second porous members 1120, 1130, and the firstand second radiopaque markers 1142, 1144, are wholly disposed within theaneurysm. The second porous member 1130 can be inserted into theaneurysm first and assume its expanded configuration therein. The firstporous member 1120 can then be inserted into the aneurysm such that thefirst porous member curves, coils, or otherwise wraps around the secondporous member 1130 as the first porous member moves to its expandedconfiguration. The first porous member 1120 is configured to be disposedwithin the aneurysm such that a portion of the first porous member isdisposed over the neck of the aneurysm. For example, the higher densityportion of the first porous member 1120 at which the first segmentoverlaps the second segment can be positioned over the neck of theaneurysm to promote endothelial cell attachment at the aneurysm neck.The second porous member 1130 can help to embolize the aneurysm byproviding additional porous mesh within the sac of the aneurysm for cellattachment and/or clot formation. As such, the second porous memberoccupies a portion of the volume of the sac of the aneurysm such thatblood flow through the aneurysm is further inhibited.

Although the medical device 1100 includes discrete first and secondporous members 1120, 1130, respectively, in other embodiments, the firstand second porous members can be differently constructed. For example,referring to FIG. 16, an embodiment of a medical device 1200 isillustrated. The medical device 1200 can include the same or similarfeatures and functions as described above for medical device 1100, orother previous embodiments. For example, the medical device 1200includes a first porous member 1220, a second porous member 1230, and aninsertion portion or member (not shown in FIG. 16) removably couplableto the first and second porous members. Each of the first porous member1220 and the second porous member 1230 can be similar in form andfunction as the first porous member 1120 and the second porous member1130, respectively, described above.

In the embodiment illustrated in FIG. 16, however, the second porousmember 1230 is monolithically constructed with the first porous member1220. It should be noted that in FIG. 16, the first and second porousmembers 1220, 1230, are shown in an expanded configuration but thesecond porous member 1230 is shown spaced apart from the first porousmember 1220 for illustration purposes only. In use, in their respectivedeployed or expanded configurations, the second porous member 1230 isdisposed within an interior region 1226 defined by the first porousmember 1220 in a similar manner as that illustrated in FIG. 15 withrespect to medical device 1100. Additionally, the medical device 1200includes two radiopaque markers 1242, 1244. A first radiopaque marker1242 is disposed at an end of a porous mesh of the first porous member1220, and the second radiopaque marker 1244 is disposed at an opposingend of porous mesh of the second porous member 1230.

In some embodiments, a medical device includes an expandable implantthat has a substantially continuous outer surface when in an expandedconfiguration. Referring to FIGS. 17A and 17B, a portion of a medicaldevice 1300 according to an embodiment is illustrated in a collapsedconfiguration and an expanded configuration, respectively. The medicaldevice 1300 can include the same or similar features and functions asdescribed herein for other embodiments. For example, the medical device1300 can include an expandable implant 1310 configured to move from thecollapsed configuration (e.g., for delivery through a blood vessel) tothe expanded configuration (e.g., for deployment within an aneurysm).The expandable implant 1310 includes at least a first portion 1320 and asecond portion 1330, and can include additional portions 1340, 1350,1360. When the expandable implant 1310 is in its expanded configuration,the expandable implant 1310 has a three-dimensional shape (e.g., asubstantially spherical shape) with a substantially continuous outersurface such that edges of at least two of the portions 1320, 1330,1340, 1350, 1360 overlap. For example, edges of the first portion 1320and the second portion 1330 can overlap, as shown in FIG. 17B. In otherwords, the expandable implant 1310 moves into the expanded configurationsuch that few or no openings or spaces remain between edges of theportions 1320, 1330, 1340, 1350, 1360 of the expandable implant 1310.

FIG. 18 is a flowchart illustrating a method 80 of using a medicaldevice to disrupt blood flow into an aneurysm and to promote healing ofthe aneurysm, as described herein, according to an embodiment. Themethod 80 includes at 82, positioning a catheter adjacent to an aneurysmof a blood vessel. For example, a distal portion of the catheter can bepositioned adjacent an opening from the blood vessel into the aneurysm.The catheter defines an elongate lumen, which can be configured toreceive at least a portion of the medical device for delivery to theaneurysm.

At 84, optionally, an expandable implant of the medical device isinserted into the catheter. The expandable implant includes a firstportion and a second portion, each of which has a first (e.g., insertionor collapsed) configuration and a second (e.g., deployed or expanded)configuration. In the second configuration, the first portionsubstantially overlaps the second portion. Each of the first portion andthe second portion also include a porous mesh. The porous mesh has afirst porosity when in the first configuration and a second porositywhen in the second configuration. The second porosity can be, forexample, greater than the first porosity. The expandable implant can bebiased in its second configuration before being inserted into thecatheter. The expandable implant is in its first configuration when theexpandable implant is disposed in the lumen of the catheter. Theexpandable implant can be inserted into the catheter after the catheteris positioned within the blood vessel, before the catheter is introducedinto the blood vessel, or any time therebetween.

At 86, the expandable implant is optionally oriented to the opening inthe vessel wall in fluid communication with the aneurysm. In thismanner, the expandable implant is oriented to enter a sac of theaneurysm when the expandable implant is moved out of the catheter, asdescribed in more detail herein.

At 88, the expandable implant is moved from a first position inside thecatheter to a second position outside the catheter. For example, theexpandable implant can be moved from a first position inside the lumenof the catheter to a second position in at least one of the blood vesselor the aneurysm outside of the catheter. As noted above, the expandableimplant is in its first configuration when in its first position insidethe catheter. The expandable implant is moved to its secondconfiguration when in its second position outside of the constraint ofthe catheter. The second portion of the expandable implant can be movedto its second configuration before the first portion is moved to itssecond configuration. In their respective second configurations, thesecond portion can be disposed in an interior region defined by thefirst portion. For example, the second portion can be moved to itssecond configuration in which it has a multi-dimensional expanded shape,and then the first portion can be moved to its second configuration inwhich it curves into a multi-dimensional expanded shape around thesecond portion.

The medical device can include an insertion portion configured to movethe expandable implant from its first position to its second position.The insertion portion can be, for example, a wire coupled to one of thefirst portion or the second portion of the expandable implant. At 90,the insertion portion is optionally disconnected from the expandableimplant. For example, the insertion portion can be disconnected from aproximal end of the expandable implant, such as after the expandableimplant has been inserted into the aneurysm. At 92, the insertionportion is optionally removed from the blood vessel through thecatheter.

After the expandable implant is disposed within the aneurysm, or othertarget vascular defect, the portion of a patient's body including theaneurysm can be imaged (e.g., using X-ray or other suitable imagingtechniques) to determine whether the expandable implant is properlypositioned within the aneurysm. For example, the expandable implant caninclude one or more radiopaque markers that are visible using X-ray. Inanother example, the patient can be injected intravenously with aradiopaque dye at a desired time following implantation of theexpandable implant to determine the success of endothelial cellattachment and/or healing over of the neck of the aneurysm following theprocedure. If radiopaque dye is visible within the parent blood vesseladjacent the aneurysm, but not within the aneurysm itself, theexpandable implant has operated to successfully prevent further bloodflow into the aneurysm. If radiopaque dye is visible within theaneurysm, blood flow from the parent blood vessel has not beencompletely prevented and additional treatment options may be consideredby the health care practitioner.

The various devices described herein can be made of any materialsuitable for the defined purpose, including, for example, drawn filedtube DFT®. DFT is available as wire, cable or ribbon. DFT is ametal-to-metal composite developed to combine the desired physical andmechanical attributes of two or more materials into a single wire orribbon system, which can be used for the expandable implant.

Filaments or wires for the braid or mesh (e.g., the expandable implants)can include, for example, filaments of materials such as MP35N,stainless steel, nitinol, cobalt chromium, titanium, platinum, tantalum,tungsten, or alloys thereof, or polyester, polyethylene (PET), Dacron,PEEK, vectron, and suture materials. Each strand may have a diameterbetween 0.0005″-0.010″, e.g., about 0.002″. In some embodiments, anouter material of the mesh or braid can be formed with nitinol that issuper elastic at body temperature, and an inner material can beradiopaque, or alternatively platinum wires may be included in the braidto provide additional radiopacity.

Suitable materials can be chosen based on their electropositivity. Forexample, an expandable implant can include titanium, tungsten, oranother material listed below in Table 1, or any combination thereof. Inuse, the electropositive material of the expanded expandable implantcreates an electrically favorable region within the vascular defect andthrough the blood, and the region in the defect containing blood, fluidor tissue is then predisposed for endothelialization to occur.

TABLE 1 PERIODIC ABBRE- COMPOSITE TABLE ELEMENT VIATION FULL NAME CHARGEVALUE 22 Ti titanium 1.36 23 V vanadium 1.53 40 Zr zirconium 1.22 41 Nbniobium or 1.33 columbium 42 Mo molybdenum 1.47 72 Hf hafnium 1.16 73 Tatantalum 1.30 74 W tungsten 1.47

In some embodiments, the expandable implants described herein can beformed with tubular braid, or sheets of woven filaments (forming a mesh,weave or fabric). The filaments can be wire or polymer or other suitablematerial. The expandable implants can be braided wire (e.g. NiTi wire),and can include a mixture of wire types and wire sizes (e.g. NiTi andPlatinum wire, and e.g. 0.001″ wire braided with 0.00125″ wire). Theexpandable implants can also be made with polymer fibers, or polymerfibers and metal wire mixed together.

The mesh of the expandable implants can be made by a variety ofdifferent forms, including, but not limited to, braiding, weaving,welding, or laser cutting. The mesh can have an operating length, forexample, in a range of about 0.5 cm to about 70 cm. In some embodiments,the mesh can have a length of 30 cm. In some embodiments, the mesh canhave a diameter in a range of about 0.5-60 mm. In some embodiments, themesh can have a diameter of up to about 10 mm when expanded (e.g., about9.5 mm for an outer porous member or portion, about 8 mm for an innerporous member or portion). The mesh can have a single density or canhave two or more densities. For example, in some embodiments, the numberof variable densities can be in a range of about 2 to about 10. Forexample, a first density can be about 100 PPI and a second density canbe about 40 PPI. (PPI=pies per inch). The braid pattern can be anypattern suitable, for example, a one-over-one configuration, ortwo-over-one configuration, etc. Strand count for the mesh can be in arange of about 4 strands to about 288 strands. In some embodiments, thestrand count is about 48 strands. Common multiples of 4, 8, 16, 24, 32,64, 72, 96, 128, 144, 192 and 288 strands for braid are available usingcommercial braiders.

A single expandable implant can include wires of the same size or acombination of 2 different wire sizes. For example, the expandableimplant can have 24 wires of 0.001″ and 24 wires of 0.0005″. The thickerwires can impart additional strength to the expandable implant and thethinner wire can provide density. In addition, any combination of wirecount, wire diameter, braid angle or pick per inch can be used to makethe mesh of the expandable implant.

CONCLUSION

While various embodiments of the invention have been described above, itshould be understood that they have been presented by way of exampleonly, and not limitation. Where methods and steps described aboveindicate certain events occurring in certain order, those of ordinaryskill in the art having the benefit of this disclosure would recognizethat the ordering of certain steps may be modified and that suchmodifications are in accordance with the variations of the invention.Additionally, certain of the steps may be performed concurrently in aparallel process when possible, as well as performed sequentially asdescribed above. For example, the expandable implant can be insertedinto the catheter concurrently with positioning of the expandablecatheter adjacent the aneurysm.

The embodiments have been particularly shown and described, but it willbe understood that various changes in form and details may be made. Forexample, although various embodiments have been described as havingparticular features and/or combinations of components, other embodimentsare possible having any combination or sub-combination of any featuresand/or components from any of the embodiments described herein. Thespecific configurations of the various components can also be varied.

For example, although the embodiments (e.g., medical device 1010)illustrated and described herein include one or two porous members orportions (e.g., porous members 1020, 1030), in other embodiments, anysuitable number of porous members or portions can be included. Forexample, in some embodiments, the medical device 1010 can also include athird porous member (not shown) having a first end and a second end andcoupled to at least one of the first porous member 1020 and the secondporous member 1030. Like the first and second porous members 1020, 1030,the third porous member can have a collapsed configuration for insertionthrough the blood vessel and an expanded configuration for occupying thesac of the aneurysm. The third porous member can be substantiallyelongate and have a width in its expanded configuration that is greaterthan its width in its collapsed configuration.

In another example, a radiopaque marker of a medical device illustratedand described can be differently positioned on an expandable implant ofthe medical device. Moreover, the size and specific shape of the variouscomponents can be different than the embodiments shown, while stillproviding the functions as described herein.

The invention claimed is:
 1. An implant configured to be positionedwithin an aneurysm, the implant comprising: an expandable mesh formedand a tubular braid flattened along at least a portion of itslongitudinal axis such that opposing sidewalls of the tubular mesh areurged towards one another, the mesh having an elongated state and adeployed state, wherein— when the mesh is in the elongated state, themesh is radially compacted and configured to be contained in a deliverydevice, and when the mesh is in the deployed state, the mesh has anarrow portion and at least first and second flattened wide portions,wherein the narrow portion is between the first and second wide portionsalong a length of the mesh.
 2. The implant of claim 1 wherein the firstand second wide portions are disc-shaped.
 3. The implant of claim 1wherein, when the mesh is in the deployed state, the mesh is configuredto contact and conform to an inner surface of the aneurysm.
 4. Theimplant of claim 1 wherein, when the mesh is in the deployed state, thefirst and second wide portions are configured to collectively form apre-determined three-dimensional shape defining an open interior region.5. The implant of claim 4 wherein the mesh further comprises third andfourth wide portions and wherein, when the mesh is in the deployedstate, the third and fourth wide portions are positioned within theinterior region.
 6. The implant of claim 4 wherein: thethree-dimensional shape is a first three-dimensional shape, and whereinthe first three-dimensional shape defines an interior region, and themesh further comprises third and fourth wide portions and wherein, whenthe mesh is in the deployed state, the third and fourth wide portionstogether form a second pre-determined three-dimensional shape that isconfigured to be received by the interior region of the firstthree-dimensional shape.
 7. The implant of claim 6 wherein an averagewidth of the first three-dimensional shape is greater than an averagewidth of the second three-dimensional shape.
 8. The implant of claim 4wherein: the narrow portion is a first narrow portion; thethree-dimensional shape is a first three-dimensional shape, and whereinthe first three-dimensional shape defines an interior region, and themesh further comprises third and fourth wide portions and a secondnarrow portion, wherein: the second narrow portion is between the thirdand fourth wide portions, and, when the mesh is in the deployed state,the third and fourth wide portions together form a second pre-determinedthree-dimensional shape that is configured to be received by theinterior region of the first three-dimensional shape.
 9. The implant ofclaim 4 wherein: the narrow portion is a first narrow portion; thethree-dimensional shape is a first three-dimensional shape, and whereinthe first three-dimensional shape defines an interior region, and themesh further comprises third and fourth wide portions and second andthird narrow portions, wherein: the second narrow portion is between thesecond and third wide portions, the third narrow portion is between thethird and fourth wide portions, and, when the mesh is in the deployedstate, the third and fourth wide portions together form a secondpre-determined three-dimensional shape that is configured to be receivedby the interior region of the first three-dimensional shape.
 10. Theimplant of claim 4 wherein the three-dimensional shape is a sphere. 11.The implant of claim 1 wherein, when the mesh in the deployed state, thefirst wide portion has a first outer perimeter, the second wide portionhas a second outer perimeter, and the narrow portion has a third outerperimeter that is smaller than each of the first outer perimeter and thesecond outer perimeter.
 12. The implant of claim 1 wherein each of thefirst and second wide portions includes a first braided layer and abraided second layer.
 13. The implant of claim 1 wherein: the meshincludes a first layer and a second layer, and when the mesh is in thedeployed state, a porosity of the first wide portion is less than aporosity of the first layer or a porosity of the second layer.
 14. Theimplant of claim 1 wherein: the narrow portion is a first narrowportion, and the mesh further includes a third flattened wide portionand a second narrow portion, and wherein the first narrow portion isbetween the first and second wide portions along the length of theimplant and the second narrow portion is between the second and thirdwide portions along the length of the implant.
 15. The implant of claim1 wherein the first wide portion is configured to be positioned over theneck of the aneurysm.
 16. The implant of claim 1 wherein at least aportion of the first wide portion is configured to positioned over theneck of the aneurysm.
 17. The implant of claim 1 wherein at least aportion of the first wide portion and/or at least a portion of thesecond wide portion is configured to be positioned over the neck of theaneurysm.
 18. The implant of claim 1 wherein the mesh further includes athird wide portion, and wherein at least a portion of the first, second,and/or third wide portions is configured to be positioned over the neckof the aneurysm.
 19. The implant of claim 1 wherein the mesh furtherincludes a spherically-shaped portion along its length.
 20. An implantconfigured to be positioned within an aneurysm, the implant comprising:a mesh formed of a tubular braid flattened along at least a portion ofits longitudinal axis such that opposing sidewalls of the tubular meshare urged towards one another, the mesh having an elongated state and adeployed state, wherein— when the mesh is in the elongated state, themesh is radially compacted and configured to be contained within adelivery device, and when the mesh is in the deployed state, the meshhas a narrow portion and at least first and second disc-shaped portions,wherein— the narrow portion is between the first and second disc-shapedportions along a length of the mesh.
 21. The implant of claim 20wherein, when the mesh is in the deployed state, the mesh is configuredto contact and conform to an inner surface of the aneurysm.
 22. Theimplant of claim 20 wherein, when the mesh is in the deployed state, thefirst and second disc-shaped portions are configured to collectivelyform a pre-determined three-dimensional shape defining an open interiorregion.
 23. The implant of claim 22 wherein the mesh further comprisesthird and fourth wide portions and wherein, when the mesh is in thedeployed state, the third and fourth wide portions are positioned withinthe interior region.
 24. The implant of claim 22 wherein: thethree-dimensional shape is a first three-dimensional shape, and whereinthe first three-dimensional shape defines an interior region, and themesh further comprises third and fourth wide portions and wherein, whenthe mesh is in the deployed state, the third and fourth wide portionstogether form a second pre-determined three-dimensional shape that isconfigured to be received by the interior region of the firstthree-dimensional shape.
 25. The implant of claim 24 wherein an averagewidth of the first three-dimensional shape is greater than an averagewidth of the second three-dimensional shape.
 26. The implant of claim 22wherein: the narrow portion is a first narrow portion; thethree-dimensional shape is a first three-dimensional shape, and whereinthe first three-dimensional shape defines an interior region, and themesh further comprises third and fourth wide portions and a secondnarrow portion, wherein: the second narrow portion is between the thirdand fourth wide portions, and, when the mesh is in the deployed state,the third and fourth wide portions together form a second pre-determinedthree-dimensional shape that is configured to be received by theinterior region of the first three-dimensional shape.
 27. The implant ofclaim 22 wherein: the narrow portion is a first narrow portion; thethree-dimensional shape is a first three-dimensional shape, and whereinthe first three-dimensional shape defines an interior region, and themesh further comprises third and fourth wide portions and second andthird narrow portions, wherein: the second narrow portion is between thesecond and third wide portions, the third narrow portion is between thethird and fourth wide portions, and, when the mesh is in the deployedstate, the third and fourth wide portions together form a secondpre-determined three-dimensional shape that is configured to be receivedby the interior region of the first three-dimensional shape.
 28. Theimplant of claim 22 wherein the three-dimensional shape is a sphere.